Did you make this instructable?

well this is basically how a hopper works. it is located on the top of the gun above the breach or the bullet reciever. the hopper is a magazine that is on the top of the gun rather than the bottom. first you load the hopper with the bullets that you want the gun to shoot. due to gravity, the bullets fall down into the breach or reciever one by one as the previous one is fired. it is really simple because all it is, is an upside down magazine. each of the bullets are dropped into the breach and fired accordingly. hoppers are most of the time a little more reliable than mags for several reasons. one of which is that gravity does the loading work for you, so you don't need rubber bands. another is that the bullets aren't being forced into eachother, so there is less friction between the bullets. i hope this helps! :)

A hopper is basically a mag that loads from the top. Make sure your hopper has low friction, so it doesnt need a pusher. A good example of a hopper would be Crestind's AST rifle, or the hopper on Perfect Duck's Red Impact.